The invention pertains to methods of forming semiconductor constructions in which a first semiconductor substrate is bonded to a second semiconductor substrate. The invention also pertains to semiconductor constructions comprising a first semiconductor substrate bonded to a second semiconductor substrate.
Technologies referred to as xe2x80x9csmart cutxe2x80x9d and xe2x80x9cwafer-bondingxe2x80x9d have been utilized to bond monocrystalline silicon materials onto semiconductor substrates. Smart cut technology generally refers to a process in which a material is implanted into a silicon substrate to a particular depth and ultimately utilized to crack the substrate, and wafer bonding technology generally refers to a process in which a first semiconductive substrate is bonded to a second semiconductor substrate.
In particular applications of smart cut and wafer-bonding technology, hydrogen ions (which can be, for example, H30, H2+, D+, D2+) are implanted into a first monocrystalline silicon substrate to a desired depth. The first monocrystalline silicon substrate comprises a silicon dioxide surface, and is bonded to a second monocrystalline substrate through the silicon dioxide surface. Subsequently, the bonded first substrate is subjected to a thermal treatment which causes cleavage along the hydrogen ion implant region to split the first substrate at a pre-defined location. The portion of the first substrate remaining bonded to the second substrate can then be utilized as a silicon-on-insulator (SOI) substrate. An exemplary process is described in U.S. Pat. No. 5,953,622. The SOI substrate is subsequently annealed at a temperature of greater than or equal to 900xc2x0 C. to strengthen chemical coupling within the second substrate.
The present invention encompasses new applications for smart cut and wafer-bonding technology, and new semiconductor structures which can be created utilizing such applications.
In one aspect, the invention includes a method of forming a semiconductor construction. A first substrate is provided which comprises silicon-containing structures separated from one another by an insulative material. The silicon-containing structures define an upper surface. A second semiconductor substrate is provided which comprises a monocrystalline material having a damage region therein. The second semiconductor substrate is bonded to the silicon-containing structures of the first substrate at the upper surface. The monocrystalline material is then cleaved along the damage region.
In another aspect, the invention encompasses another method of forming a semiconductor construction. A first substrate is provided which comprises silicon-containing structures separated from one another by an insulative material. The silicon-containing structures define an is upper surface. A second semiconductor substrate is bonded to the silicon-containing structures at the upper surface. The second semiconductor substrate comprises a mono-crystalline material. At least one doped silicon region is formed to extend through the monocrystalline material and to electrically contact at least one of the silicon-containing structures.
In another aspect, the invention encompasses a semiconductor construction comprising a first substrate having silicon-containing structures separated from one another by an insulative material, and a second substrate comprising a monocrystalline material. The silicon-containing structures of the first substrate define an upper surface, and the monocrystalline material of the second substrate is bonded over the silicon-containing structures at the upper surface.